Endometriosis is one of the more common — and commonly misdiagnosed — conditions affecting women’s reproductive health. It is estimated to affect approximately 10% of women of reproductive age, and its impact on fertility is significant though variable. For women over 35, endometriosis raises questions that involve both the condition itself and the overlay of age-related fertility decline. Understanding what the research says helps frame these questions more clearly.
This article provides a research-informed overview of endometriosis, its effects on fertility, why age adds complexity, and what current evidence suggests about pathways to conception. As always, individual circumstances vary widely — working with a specialist is the most appropriate way to address your specific situation.
What Endometriosis Is
Endometriosis is a condition in which tissue similar to the lining of the uterus grows outside the uterus — most commonly on the ovaries, fallopian tubes, and the tissue lining the pelvis. This tissue responds to hormonal signals in the menstrual cycle, thickening and shedding with each period. Because it has no way to exit the body, this process causes inflammation, scarring, and adhesions over time. Common symptoms include pelvic pain (particularly during menstruation), pain during intercourse, and heavy or irregular periods — though some women with endometriosis have no symptoms and are diagnosed only during investigations for infertility.
According to the National Institute of Child Health and Human Development, the cause of endometriosis is not fully understood, and diagnosis typically requires laparoscopy — a surgical procedure — for confirmation. This diagnostic delay contributes to the average gap of 7–10 years between symptom onset and diagnosis that is documented in the literature.
How Endometriosis Affects Fertility
The relationship between endometriosis and fertility is complex. Research indicates that endometriosis can affect fertility through multiple pathways: ovarian involvement can reduce ovarian reserve and egg quality; inflammation can affect the quality of the peritoneal environment for egg release and fertilisation; adhesions and scarring can distort pelvic anatomy and block the fallopian tubes; and the presence of endometriomas (cysts on the ovaries) may directly damage follicle-containing tissue.
The severity of endometriosis does not always predict its impact on fertility. Some women with severe endometriosis conceive naturally; others with minimal disease have significant fertility challenges. The relationship between endometriosis stage and fertility outcomes is not linear. For context on the range of fertility factors that can be evaluated, fertility evaluations after 35 covers what comprehensive assessment involves.
Why Age Adds Complexity After 35
For women over 35 with endometriosis, age-related ovarian reserve decline and endometriosis-related ovarian damage may compound each other. Research suggests that endometriosis is associated with an accelerated reduction in ovarian reserve over time — meaning that women with endometriosis who delay fertility treatment may face a more compressed window than women of the same age without the condition. Surgical treatment of endometriomas (ovarian cysts caused by endometriosis) also carries a risk of reducing ovarian reserve, which requires careful weighing of benefits against risks.
This makes timely specialist assessment particularly important for women over 35 with known or suspected endometriosis. The question of whether and when to pursue surgery, and what fertility preservation or treatment options are most appropriate, is highly individual and benefits from specialist input. For context on ovarian reserve, ovarian reserve after 35 covers the assessment and implications.
Pathways to Conception With Endometriosis After 35
Many women with endometriosis — including those over 35 — conceive naturally, particularly those with less severe disease. For others, assisted reproduction may be recommended. IUI (intrauterine insemination) and IVF are the most commonly used options; IVF success rates in women with endometriosis are somewhat lower than in those without the condition but remain meaningful. The decision between expectant management (trying naturally), medical treatment, surgical treatment, or proceeding to assisted reproduction depends on disease severity, ovarian reserve, partner fertility, and individual preferences and timelines.
Frequently Asked Questions
How do I know if endometriosis is affecting my fertility?
A comprehensive fertility evaluation — including assessment of ovarian reserve (AMH, antral follicle count), a hysterosalpingogram (to check tubal patency), and pelvic ultrasound to look for endometriomas — can identify some effects of endometriosis on fertility. However, a definitive endometriosis diagnosis requires laparoscopy. If you have symptoms consistent with endometriosis and are having difficulty conceiving, a referral to a reproductive endocrinologist or specialist in endometriosis and fertility is appropriate.
Should I have surgery to remove endometriosis before trying to conceive?
The evidence on whether surgical treatment of endometriosis improves natural conception rates is mixed, and the decision depends strongly on the type and location of disease. For mild-to-moderate endometriosis without endometriomas, research does not clearly show that surgery before attempting conception improves live birth rates. For endometriomas specifically, the evidence is even more complex, given the risk of reducing ovarian reserve. This decision should be made collaboratively with a specialist who can weigh the specific risks and benefits for your situation.
Does endometriosis always worsen over time?
Not necessarily — endometriosis is a highly variable condition and does not follow a single predictable course. Some women experience progressive worsening; others have stable disease for years. Pregnancy and breastfeeding are associated with temporary improvement in some women due to the suppression of the menstrual cycle, though the condition typically recurs. Hormonal treatments used to manage endometriosis symptoms are not compatible with trying to conceive, which is why specialist input on timing and approach is particularly valuable.
Key Takeaways
- Endometriosis affects approximately 10% of women of reproductive age and can impact fertility through multiple mechanisms.
- After 35, the combination of age-related and endometriosis-related effects on ovarian reserve makes timely specialist assessment important.
- Disease severity does not reliably predict fertility impact — some women with severe endometriosis conceive naturally.
- The decision between expectant management, surgery, and assisted reproduction is highly individual and benefits from specialist guidance.
- Women with known or suspected endometriosis who are over 35 should not delay seeking fertility assessment.
This content is for informational purposes only and does not constitute medical advice. Individual health situations vary significantly. Always consult a qualified healthcare provider before making decisions related to your health, fertility, or pregnancy.
About the Author
Emily Carter is a women’s health writer focused on fertility, pregnancy after 35, and sleep changes in midlife. She writes research-informed, non-alarmist content to help women navigate reproductive and hormonal transitions with clarity and confidence.